For what procedure? In general, less is better. So, if it can be done with local comfortably, that's good. In some cases local is not sufficient, and suffering to avoid general anesthesia is not better.
Both. Can achieve the goals of patient comfort, minimization of pain, reduced anxiety and minimal patient movement and recall, assuming that either is an accepted way of creating optimal surgical conditions. Neither is considered better, as long as surgical goals and patient comfort can be assured.
Depends. Depends on the type of the procedure , patient ( airway, comorbidities, tolerance), surgical skills. Anesthesiologist for the particular case is the best to decide.
Both. These are two different anesthetic techniques that are better for different purposes. Have a hang nail, local. Need your appendix out? General. A straight local is used for short minor procedures that are minimally invasive. General anesthesia is preferred for longer more complex and more invasive procedures. .
Local if feasible! Far less complication with local. Certainly it has its limitation besides surgeons prefer the general anesthesia. As one british surgeon told me after telling him that I do varicose vein surgery in office setting and local: "do I have to entertain the patient too"?